Is it possible to use RB hAP Lite as an AP and also a sniffer? All shoul be on 2,4 band.
Maybe with some additional hardware? or even there is some mikrotik device which may do that?

In my case one 2.4 wlan shoul be as guest Hotspot point and second shoul be as a sniffer to track amount of clients in the shop.

You can run WiFi scan in the background, without stopping the AP function. Just click "Scan" on the interface, and select "background scan". Then you can monitor other APs in the area, without disrupting the AP clients.

But Scan only looks for other APs. If you want to run Wireless Snooper or other tools, the interface can't also serve clients at the same time. Then you need something with multiple interaces and hAP can't do this.

Thanks!

I need to get Wi-Fi Probes in order to know how many peaople are near my AP, also separate them into three grops (near, middle, far)...
I may do it, when sniffer is running, but as you said then my clients can't connect to the HotSpot.

Is there any Mikrotik device when can do that?
All should be on 2.4GHz band.

No there isn't.
What are you trying to do exactly? Why do you need to know how many people are near your AP but are using some other WiFI ?

I have a business case where i need to give my clients an internet access via HotSpot. There are a lot of such points (hundreds of locations) all are Mikrotik routers. Also i need to know how may people are going though my points ( say, very short interaction time of sell phone and access point ), how may peoples stays around (say they are in location or near more then 5-10 minutes) and so on.
All that i may do with sniffer, i may grab wifi probes and compute distance, interaction duration ...
It is very important.
And as i already uses Mikrotiks (as i said hundreds of routers), i have wrote all required scripts for them, i prefer to stay with Mikrotik.

Unfortunately, but most probably, should switch to RPI3 with an additional USB WiFi modules.

Is this "very important" way of tracking people legal in your country? As far as I know iOS devices as well as the latest Android versions already randomize their mac address when probing for wifi networks as countermeasure to this kind of privacy violation.

I have checked and yes, it is legal, As i do not save and display any information about client, also all info are faceless/impersonal (no any phone numbers/names/age/etc is tied to the MAC )
MACs on android, at least at my tests are 100% real. iOS around 70-90% depends in version of iOS.