Do objects know what item is in their slots?

I wanted to create a 1 tile bathroom and found that too hard so what i did instead was slot all the pieces together to make the bathroom which works. Then I thought the idea of clicking each object would get annoying, so I'm wondering if my main object the shower can link to its subjects/slots(toilet and sink) add their main functions to the pie menu so you only need to click the shower to access the other functions. Is this possible or does anyone have any different ideas?