Splitting your character group is very useful! It can create new scenarios and subplots for you to explore. Here are some ways to do so:

-your characters have to split because their abilities correspond to the different ways (character a goes to the fire chamber bc he has fire powers, character b goes to the ice chamber bc he has ice powers)

-the villain manually splits them for divide and conquer

-they get lost and accidentally split up

-the other characters are aware of two characters chemistry, so they send them off alone for some quality bonding time

-splitting up to cover more ground

-one group has to hold down the base, while the other needs to explore

-there's a fight and the characters storm off in different directions

-someone's afraid of the place being explored, so they need to stay back/go a different way

Those were just some ideas? Is this useful? What other plot ideas would you like? Specific topics like this, please