Hi Kaklop,
Welcome to the Apple Community.
Apple support has helpful articles online:
Sync contacts and calendars between your Mac and iPhone or iPad
https://support.apple.com/en-au/guide/mac-help/mchlf24d4e49/mac
iPad (iOS14) User Guide:
Lists "Contacts" under "Apps" but doesn't seem to mention Groups.
https://support.apple.com/en-au/guide/ipad/welcome/ipados
Wondering if you use iCloud ?
Use other contact accounts on iPad
NB. Tap Groups, then select the groups you want to see.
This button appears only if you have more than one source of contacts
https://support.apple.com/en-au/guide/ipad/ipad99df07d1/ios
Hope this helps you :)