Displaying Taxonomy Terms which are used by a Content Type I have created a taxonomy named Category which has a number of terms like Agriculture, Business, Computers, etc.

I have created three content types viz. Products, Suppliers and Buyers. All of these types use the terms from the Category taxonomy.

What I am trying to do is create a block named Supplier Categories which as the name suggests, displays a list of terms from the Category taxonomy which are associated to Suppliers. So say if you have Suppliers associated to the Agriculture and Business categories then this Block should show them. It shouldn't show Computers though because no Supplier uses this term.

I am not sure whether this is possible or not but I have spent a lot of time playing with blocks but I couldn't get it to work.

By the way, I am trying to do this using Drupal 7.
You should use Views. Here are the steps to do to achieve what you would like to do:


Create vocab. "Category":


Create content type "Suppliers" with a "Term reference" field to "Category" vocabulary:


Create three "Suppliers" contents in "Agriculture", "Business" and "Blabla" categories - so these 3 should be listed in your block.
Add a new view at admin/structure/views/add with these settings:


Add a new field "Content: Category":


(here are the settings)
Remove "Content: Title" field (1 , 2)
Set some descriptive names (like machine name, block name, display name, etc.), AND set Sort Criteria to "Content: Category (asc)":


Save
Go to admin/structure/block, set "Supplier Categories block" to be displayed in the "First sidebar" (or "Sidebar first" in Bartik) or any other, then hit "Save blocks":


You are ready.