Subset editor for title should allow multi-selection
Is your feature request related to a problem? Please describe.
When the subset editor is launched from a hierarchy on filter it allows only selection of a single element. This is OK for clicking OK and setting the element for the filter. However, it is extremely annoying as it doesn't allow the set of members to be editedand results in much more work for the user to search for elements to select.
Describe the solution you'd like
Even when launched from a filter positon the subset editor should allow the list of members to be edited as normal (e.g. multi-select for keep & discard actions) and only when clicking OK apply the rule of single element selection.
What woudl be even better is if multiple elements are selected when clicking OK would be for the user to be prompted if they want to create a calculated member using aggregate.