textItem completion with valueMap does not work

I created a TextItem and gave it a valueMap, and it does not use it for completion.

What I am really trying to do is let the user write a number of attributes from the map with the help of completion/suggestions.

I tried using a SelectItem insted ,which worked with the ValueMap but it does not allow me to write the fields on my own and simply suggest from the map, like it does in a ComboBox.

The ComboBox works well but it does not allow multiple values completion.

can you help me find a way to make one of these things work?

SelectItem has a mode allowing multiple selection where you can pick multiple values in a drop-down. If you want dynamic auto-completion, you could build it yourself starting from TextItem, or use Feature Sponsorship to have it added to the framework.