Adding categories to a tag field a good idea?

Question

I'll try to simplify my question as much as possible.

I've created a dialog where you can add "items" to "objects". For this, i added a simple tag field in the dialog. The user can add the items by typing in the name of this item.

Now, elsewhere in the system, you can categorizes these items. Meaning you get an item list like:

• Group 1
  • Item 1
  • Item 2
  • Item 3
  • Item 4
  • Item 5
• Group 2
  • Item A
  • Item B
  • Item C
  • Item D

Now, if the user wants to add an entire category to an object, is it acceptable to just type in the category into the tag field? And how do you handle this? Do you leave the category as a tag, or do you replace them with all items in that category?

or

Answer 1

Gmail uses the first option that you have provided for adding group of contacts to an email. This approach works well when it is not necessary to know what items go under what group. If that is not your case, you may try one of the following options.

Option 1-

Delete the group as a whole or delete individual items within the group. Option 2-

When individual items of a group cannot be deleted (the group goes as a whole). Hover over a group to see the items included in that group.