You can create Relationships between
Contacts and Contacts
Contacts and Users
...
map the relationships that contacts have with each other and with your colleagues
...
Relationships
Create different types of relationship
Add those relationships to contacts
Contacts can have many of the same relationship
If you want you can add start dates and end dates to relationships but both are optional
Watch the walkthrough
https://www.loom.com/share/bc037e26c3c8447db3306cce596d1fed