On adding "Override" to "New Volume Profile" asset then it causes the editor to throw NullReferenceException, refer to the attached video.

Steps to repro:
1. Create a new Project
2. Windows > Package Manager > Core RP Library > Install
3. Project Window > Right Click > Create > Volume Profile
4. Project Window > New Volume Profile > Inspector > Add Overried > press Enter key

Actual Result:
NullReferenceException in the console when adding Add Override on New Volume Profile asset

Expected Result:
No Error in the console

Reproducible On:
2020.2.0a17, 2020.1.0b15 with Package Version Preview.13 - 9.0.0, 8.0.1,
2019.3.0f5 with Package Version 7.1.8,7.1.7

Environment:
Windows10 and macOS 10.14

Stack Trace:
NullReferenceException: Object reference not set to an instance of an object
UnityEditor.Rendering.FilterWindow.OnGUI () (at library/packagecache/com.unity.render-pipelines.core@9.0.0-preview.38/editor/filterwindow.cs:374)
UnityEditor.HostView.OldOnGUI () (at <fc44262c43cd402d975d22277bf4bb54>:0)
UnityEngine.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 parentTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout, UnityEngine.Rect layoutSize, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, UnityEngine.Matrix4x4 worldTransform, UnityEngine.Rect clippingRect, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Boolean canAffectFocus) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.IMGUIContainer.SendEventToIMGUIRaw (UnityEngine.UIElements.EventBase evt, System.Boolean canAffectFocus, System.Boolean verifyBounds) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.IMGUIContainer.SendEventToIMGUI (UnityEngine.UIElements.EventBase evt, System.Boolean canAffectFocus, System.Boolean verifyBounds) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.KeyboardEventDispatchingStrategy.DispatchEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.EventDispatcher.ApplyDispatchingStrategies (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, System.Boolean imguiEventIsInitiallyUsed) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.EventDispatcher.Dispatch (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, UnityEngine.UIElements.DispatchMode dispatchMode) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.UIElements.EventBase e, UnityEngine.UIElements.DispatchMode dispatchMode) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) (at <434515d9f4bb4f26bab9aa61f75e4922>:0)
UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) (at <9e3b197786024cdcb531b292c5998102>:0)