Assiduousness

For the duration of the spell, you manipulate your personal timeline and can maintain concentration on up to two spells at once. One of the spells must be of 3rd level or lower or the spell fails, but it can be cast from a higher level spell slot. The spells share a concentration roll made to maintain them.

At Higher Levels. When you cast this spell using a spell slot of 9th level, the lower level spell can be of 4th level or lower.