Hi guys, I found a solution (odoo8) :

<button string="New Project Based on Template" name="duplicate_template" states="template" type="object" t-attf-data-context="{'parent_id' : {{record.parent_id.raw_value[0]}}}" class="oe_highlight" groups="base.group_user" ><span>Create new Project</span></button>

I can confirm that the option from Remi still works in Odoo 11:

This works for both buttons and a

<a 
    name="action_you_want" 
    type="object" 
    t-attf-data-context="{'id' : {{record.id_field.raw_value}}}">
    Link string
</a>

Remi Francois:

Your solution does not work for me in v7. I receive an error

Error: QWeb2: Error evaluating template: SyntaxError: missing ) in parenthetical

Same for me - it seems that there is no way to pass context in a kanban view to the called action :(

I did ask more or less the same question here: https://www.odoo.com/forum/help-1/question/how-to-pass-context-to-a-called-action-with-kanban-view-links-or-buttons-83722