ComboBox with select all Columns

I want to create a ComboBox with a select all column, something like this:

adding somewhere (top left or bottom left) a select all button or something similar, which can automatically check all the choice. How can I do that?
I know hot to use the basic ComboBox, but I didn’t figured out how to add such functionalities.
Thank you for the help.

I remember there being a quite similar question somewhere on this forum but i couldn’t find it after a quick search.
Basically there are 2 ways (atleast as far as i remember) to have checkboxes inside a Combobox:

  1. Using the checkbox marks from the Wingdings font and switch them on ValueChange
  2. Don’t use a Combobox but instead a PopupButton (It’s an addon) which opens a popup right under your button containing a table with the checkboxes

A Check all would be implemented different depending on what method you’re going to use. Basically when check all is clicked you will iterate over some array/container and set some value to true for all of them.