When creating or editing an opportunity work stack, you can filter by Opportunity Owner as well as Additional Opportunity Owner.
There is one set of filters for each.
By default, an opportunity will only be considered a match if both the Owner, and Additional Owner filters match.
However, you can use the Include Owner or Additional Owner option to relax these requirements.
If checked, any user selected in either the Opportunity Owners or Additional Opportunity Owners sections will be matched against all owners of an opportunity, regardless of whether they are the primary / default owner or not.
So, if you want to create a stack to see all opportunities where you are either the primary or an additional owner, you can check your own name in either or both of the owner sections, and check the Include Owner or Additional Owner box.
How to tell which owner is the primary owner
On an opportunity record, the primary owner is the user marked as Default. Additional owners are any non-default users in the Opportunity Owners section.
Work stacks will also show the default owner under the Owner field, and any others under the Additional Owner field.
