Entity is a way to organize and color-label documents/folders in a vault. It’s like having multiple filing cabinets in a vault that allows for independent or combined dynamic views and collaboration. In the new version v4, we have segmented the 'Entities' feature into 'Assigned Entities' and 'Roll Up Entities'.
This is the entity that is assigned to a folder e.g. 'Statements' in the screenshot. Now, there may be files or subfolders within the 'Statements' folder with different entities but Assigned Entity will only show the entity assigned to the 'Statements' Folder and not files/subfolders within.
Roll Up Entities
Roll Up Entities for the 'Statements' folder would list all the entities that are assigned to each file/subfolder within the 'Statements' folder. For e.g. In the below screenshot, entities for Test 1 is Green+Grey and for Test 2 is Pink+Grey. Since both documents are within the Statements folder, thus Grey, Green and Pink would show under Roll Up Entities for 'Statements' folder.