Trying to add a customised filter in Sales Order List View.

I can apply individual filters, but I can't put them into a single command line that does it all...

I've tried to apply ['&', but couldn't get it to work, help~~~~

Below are lines of my single filters that I want to combine into 1 'mega' filter

(had to add a space after the first < , otherwise it won't show up in here)

< filter string="Active Order" name="Status" domain="[('state','=','sale')]"/>

< filter string="Active Order Unpaid" name="Next activity summary" domain="[('next_activity','!=','Paid')]"/>

 < filter string="Active Order Not Done" name="Next activity summary" domain="[('next_activity','not ilike','Done')]"/>