I have a site hierarchy like this:
I want to create a workflow to process a list item in c1 and under some conditions pass it to another list in c2 or as a workflow variable in p.
How it is possible in SharePoint2010?
You can create a workflow with association form. On this form the user should set destination site and list, after this you can retrieve this values in the workflow properties and process item. How to create association form you can see here. If you would like to set the different sites and list for each items you can use initiation form. But in this case workflow should be run manualy by user.