In the 5e Adventurer’s League 7.0 Guide, there’s an option listed for players to “catch up”:
Downtime: Catching Up. Sometimes you might like to advance to the next tier to catch up with friends, play new adventures, etc. “Catching Up” is an available option at 4th, 10th, and 16th level, and advances your character to the next tier of play. In order to do so, you must pay a number of downtime days determined by your current level, as follows...
Is there context necessary for a character to invoke the Catching Up clause? For example, if a character is adventuring in a different game to catch up with friends in a separate game, can a player invoke this in their logsheet to catch up or are they limited by the current adventure? If it is limited by the current adventure, then what about campaigns like Tomb of Annihilation where Tier 1 characters can stumble into Tier 2 and 3 areas. Do players have autonomy to invoke this between sessions or is this completely at the whim of your DM that day?
In sum, is this a “private” player autonomous action on the character's log sheet - or is this an action that requires a DMs exclusive permission?