For this workout you just need some floor space and a light weight. It doesn't even have to be a dumbbell, could be a bottle of water or similar too! There are 4 exercises in this workout:
V sit with alternating single arm weight hold - 5 reps each side
Plank rotation with shoulder tap - 5 reps each side
Leg extension & lift - 5 reps each side alternating
Roll up and woodchop - 5 reps each side alternating
You can choose how many rounds you do, but 3-5 would be a good range to work within. You can do this as a standalone workout or at the end of another to add on some core focussed work.
Here is a follow along video where I explain the exercises and you can workout with me and my dodgy rep counting: