If you want to use an action available on the form view in the tree view for the selected records:

1) Go to the form view and check the name of the action you want to use (by leaving your mouse on the button in debug mode) - see attachment

2) Go to Configuration / Technical / Server Action and create a server action using this code

context = dict(env.context)
invoice = env['account.invoice']
for rec in invoice.browse(context.get('active_ids')):
    rec.action_open_invoice() 

Comments:

- "invoice" is a variable name you can change

- you can change the env you want to use (account_invoice = model name of invoices)

- change the action name and add "()" at the end

3) Create a contextual action for your server action (green button on the server action)

//!!\\ In V10 you should replace rec by object:

context = dict(env.context)
invoice = env['account.invoice']
for object in invoice.browse(context.get('active_ids')):
    object.action_open_invoice()