Hi Bozena & welcome to the forum.
We would call this a split level station. They are uncommon, but we have (or have had in the past) a few in the UK.
The closest to me in the South East was at
East Grinstead in West Sussex. This had High Level and Low Level stations crossing each other at right angles (90 degrees), but the High Level station closed in 1967 and was demolished in 1970. The Low Level station is still open for traffic.
https://en.wikipedia.org/wiki/East_G...ailway_station
http://www.disused-stations.org.uk/e/east_grinstead/
Currently operational split level stations in the UK include:
Tamworth station, Staffordshire
https://en.wikipedia.org/wiki/Tamworth_railway_station
https://www.search.staffspasttrack.o...=2&ThemeID=272
Lichfield Trent Valley station, Staffordshire
https://en.wikipedia.org/wiki/Lichfi...ailway_station
http://www.railaroundbirmingham.co.u...ent_valley.php
Retford station, Nottinghamshire
https://en.wikipedia.org/wiki/Retford_railway_station
https://www.nationalrail.co.uk/stati...d-station-plan
These are the only stations that I know of in the UK but there may be others! There are also several examples of stations with parallel platforms at different levels (including London Bridge, St Pancras International and Portsmouth & Southsea for example) and these would also be known as split level stations.
Hope this helps and good luck with your project.
Tony