How to create a collection to use in a subprocess ?

Hi,

I want to create a collection to store Uuids of the assets that are found using a relation and filtered on specific attribute value, which I want to use in a subprocess.

for example I want to create a collection for a report which has 10 report attributes and 5 have some attribute values And I want to create an collection for these 5 elements only.

My approach is to use a  find relation method to get to the report attributes and then navigate through each report attribute to check for the conditional attribute value if present add it into the collection.
Could you please guide me with a code snippet for the above example?

Thanks,

Abhishek