All of the timing functions output a millisecond counter value. This vaule will be the same across all of the functions.
So when you hit your start button, you need to grab the current ms timer value using the 'Tick Count' function. Put this function inside the first frame, but outside the loop and wire the value into the loop. Then inside your loop, monitor the tick count from the 'Wait' or 'Wait until next ms Multiple' function. Subtract that value from the original value to get elapsed time. Use something like the 'Greater than or Equal to' function to compare the elasped time to the time you want to run the loop and connect its output to the loops stop terminal.
Do this in each loop and you should have what you need.
You can probably even get rid of the sequence structure if you just wire some value from one loop to the next. Even if you don't pass that value into the loop, wiring to the edge will prevent the loop from starting until the previous has stopped and put a value on that wire. This is Dataflow.