Select2 offers a customisable selection box with support for search, tagging, remote datasets, infinite scrolling and many other widely used options. You can see some examples of how it works here in their documentation: Select2 Documentation
The reason for using Select2 is to turn multi-selection options into tags, i.e. instead of having a list with all the options and do Ctrl+Click to select multiple options, I will have a search bar to filter options by typing and when selecting them, they will be added as tags. Here you can see an example: Select2 example
I am using the BuddyPress Xprofile Custom Field Types plugin as it enables direct integration with Select2, but this is optional, as the Select2 documentation explains how to implement a multi-select field and make it compatible with Select2.
In any case, I have tried both ways and neither worked for me. The result should be similar to the one shown in my previous reply but I have the problem I showed in previous screenshots.
