On Signitic, you can add links to each of your groups, for example, if they represent different brands. In this situation, there is a concept of inheritance that allows you to apply the links from your level 1 group to your level 2 or 3 groups, for example. (Parent data inheritance)
Pins are specifically used to avoid this situation. By going to group 2 or 3 and pinning the Facebook network, for example, it will not take the information from level 1 and thus will not display the network in question on the user signature of the said group.
Add the pin to your group
To add your pin, go to the relevant group, then click on the Links sub-tab. Locate the relevant field and click on the pin.

Once done, the field will turn red, confirming that the pin has been set.

Don't hesitate to contact support for more details.