Is there anyway to cross reference a view? I have View1 where I would like to add a filter which stops any rows appearing if there are rows in View2.

I thought I would have been able to execute some PHP as a filter, but I can't see any options for that.

Is there any way to use another view as a filter?
For this you could use the advance option of the view where you could add the contextual filters and relationships.
This would help you in filtration.

For php filtration you could use the Views PHP module; that would help you in your filtration.


  This module allows the admin account (user 1) to add fields, filters and sorts to views which use PHP code. It also supports additional accounts when the core PHP Filter module is enabled.


For information about how to use the module you could refer to README.txt of the module.