Forms :: Show / Hide Main Form Buttons When Clicking Into Subform

I'm currently building a database in Access 2013. I've used Access many years ago, and not really in anger since maybe 2003, so I've been re-learning quite a lot. Here's an overview of my scenario, and issue:

The main purpose of my database is to allow engineers to log various bits of information when building, servicing and testing manufactured products for offshore exploration. Because some of the engineering team aren't so great with data entry etc, I've decided that, rather than deleting data, I'm going to use a 'deleted' flag: user clicks what he considers to be a delete button, but in reality an update query will simply update the flag and, because the form is built on a query which includes a 'where deleted = 0' filter, it'll no longer be shown. This will allow us more control over the data and will also allow me to check that everything is running okay.

My main forms include a number of subforms, including one which includes a second tier of nested form: Pin Maps for (electrical) Connectors.

What I need to achieve is fairly straightforward: as the user navigates around the form, I'd like a 'delete' button which is specific to that subform to become visible and for any other 'delete' buttons to become hidden. Once tested, the buttons would be 'stacked' in the same position at the top of the main form, so the user just thinks they're deleting the relevant record in the sub, or main, form.