Just kind of are,it doesn't work brilliantly but we're just cracking on best we can. DH and I are both WFH, DD is 5 so we are able to get her to do some activities bury herself but only for 20 mins or so at a time on a good day.
We have a list on the wall of 'Go to' activities that usually work to keep her occupied so we don't have to think of things off the top of our heads in a pressurised moment.
We have been using evenings to catch up on work and getting started earlier in the day too so if we need long breaks during the day it ends up working out.
Been ensuring we do a long walk every day or spend a decent amount of time in the garden as outdoors time wears her out and keeps her from going stir crazy.
Bosses know we have a child running around so at the beginning of each call/conference call we do a little 'sorry if DD decides to join the conversation' and everyone gets it, lots are in the same boat so are pretty understanding.
Also don't stress the mess, unfortunately it seems that the most interesting and engaging activities create chaos. DD is loving chopping up balloons to make Barbie clothing.
For 2s and under I'd recommend things like a storage tub full of super duper cheap cereal, and plastic cups/spoons so they can move the cereal between containers. Or set them up in the (empty) bath with bubbles to blow and/or small toys that have been frozen in water or set in water with gelatine so they have to melt/break them out. You can sit in the bathroom with your laptop while they play.