Use same Pump for water booster and tank filling

[temp122616]

I have a water tank to fill which have a float valve, and I want to install a water booster pump that boosts the water coming out of that tank.

Usually, you install a pump on the inlet of the tank to fill it, and you install another pump on the tank outlet to boost water towards the faucets

the problem is as follow:
I need to the same pump to do both jobs, to fill the tank and to boost water out of the tank to the faucets.
How can I install such a system?

 

[Valveman]

Here is a picture of a cistern with a booster where you can pump directly from the well pump or from the booster.