Hi @cabutbul So you are trying to set a combo box depending on another which the field in you SharePoint list is a choice column? This will then filter a table?
So, the way that I achieved this is I have a SharePoint list called movies a name column which is text and a genre column which is a multi-select choice column:
Text Coul Combo box:
This is listing all the distinct name in my table as the items property:
Distinct(Movies,Name)

Then for the genre combo box I have the following for its items property:
Choices([@Movies].Genre)

Then I will set the default selected items property to the following look up:
LookUp(Movies,Name = ComboBox7.Selected.Value,Genre)

As you can see this returns me 2 values Horror and Thriller for Scream.
Hope this helps!
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Thanks
Andrew