can we determine distance between esp8266 and phone connected to it

i want to determine distance between esp8266 and 2 phones connected to it and display it on arduino's serial monitor. please send me the code for same please help

You can measure the signal strength with the WifiRSSI function but its a very poor measure of the distance to the source. Consider that most mobile phones have some kind of shielding to reduce the amount of RF energy going into your head- this means signal is going to be weaker on that side than the other.