Ok, the below appears to work.
Category List View
Global
Triggers: joomla_onContentAfterDisplay
Type: CB Activity
User: Self
Access: Everybody
Conditions
Field: Custom > Value
Custom Value: [var1]
Operator: Equal To
Value: com_content.categories
Action
Mode: Stream
Stream: Comments
Asset: category.[var2_id]
Output
Display: return
Layout:
Code:
<div class="cb_template">[content]</div>
Method: HTML
Category View
Global
Triggers: joomla_onContentAfterDisplay
Type: CB Activity
User: Self
Access: Everybody
Conditions
Field: Custom > Value
Custom Value: [var1]
Operator: Equal To
Value: com_content.category
Action
Mode: Stream
Stream: Comments
Asset: category.[var2_id]
Output
Display: return
Layout:
Code:
<div class="cb_template">[content]</div>
Method: HTML
Again, this is all on Joomla. What context you check against is dependent on the Joomla views usage of onContentAfterDisplay and where the comments are placed are dependent on the Joomla views output of onContentAfterDisplay. For category lists for example this is unfortunately at the very top for whatever reason. Those were the only 2 relevant contexts I could find. You can enable Debug under the Parameters tab of your auto action to see what your condition is checking against as well.