Group Filter Functionality

Group filter allows dynamic filtering of one section, however when there are many options it is quite difficult to scroll and select.

Firstly, could we use a key index sequencing (same as the list functionality) within the grouping, then users can find options a bit easier as we can go alphabetical rather than always by No.

Second ask is if we can search through this filter which is a less useful one. I've said to the customer if they needed to search as the options were so many, they may as well search within the full list. But if this search could work on both the list and within the filter, then it would be a great benefit.
Example: I search for London on the list, this searches and displays all records with London as usual, but also searches through the grouping. I can then either click on the record I want or click on the grouping result to specify it even further.

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