Use IsMemberofGroup with runtime variable

Currently, we must use static text for the SharePoint group name with the IsMemberOfGroup and can only be used inline.

If a SharePoint group is added to a people-picker column, there's no feature to check if the current user is a member of that group from the people picker column and use that in a formula in a calculated field.
It would be super useful if we could use IsMemberofGroup with Named Controls and Runtime Functions.