I have a question concerning the attribute table of QGIS (2.18 or 3.0):
Short: I would like to have a field which is a link, but not to external data (like a picture) but to a the attribute table of an object on an other layer.
Longer: I need to connect the attribute forms of several objects on several layers. For example object-1 of layer-1 has a connection to object-2 on layer-1 and object-3 on layer-2. Now I created a layer for all these connections. There I would like to have field with a link, which opens automaticaly the attribute table in "form view" of this connected/linked object (which is on an other layer). In the settings I can connect or join different layers, and I can set the "widget type" to "attachement" to create a link. But is there a way to set up such a link, which leads to the attribute table of an object which is on a seperate layer, and if yes, how could I set this up?
P.S. Because the objects have spatial datas too, QGIS would be preferred, but if there is no way to do this in QGIS, maybe with an other software (preferable OpenSource)?
Edit: I "draw" in the qt-designer quickly the form I would like to have:
and now I would like to define, that when I click on "Link to Attribute Form Dataset 1" the attribute table of this dataset opens: