No, there is no hidden or private league option in Nettla. A league round shows in the app from its Registration start date. To keep a league out of sight, archive it, or share the round link directly with the group you want.
Your options
Share the round link: open the round in Play → Leagues and click the link icon (Copy the player app link to this round). Send it to the group, for example a company or university.
Control when it appears: a round only shows in the app from its Registration start date. Until then, players can't see it.
Archive the league: archived leagues don't show in the app. Open the menu on the league card in Play → Leagues and choose Archive. Use Reactivate to show it again.
Good to know
Once a round is visible, any player in your club's app can find it.
To limit who can join, turn off Standard Entry Price and set entry prices only for the cohorts that may join.
Leagues is an add-on that Nettla switches on for your club. If you don't see Leagues under Play in the sidebar, contact Nettla.