How to cut string between two search patterns(including search patterns) from a file?

I have a file called applications.txt which contains the following data :

MOB-x01gmobdb2a-PRD-IBG
TDST-AB-x01gtdsdb1a-UAT-CST
ABC-x01gabcdb2a-PRD-CBG
PQR-x01gpqrdb1a-UAT-IBG
XYZA-GZ-x01gxyzdb2a-PRD-TS
UVW-x01guvwdb1a-UAT-IBG

The strings in this file contain hostnames which I would like to display as follows :

x01gmobdb2a
x01gtdsdb1a
x01gabcdb2a
x01gpqrdb1a
x01gxyzdb2a
x01guvwdb1a

Few of the above servers are UAT and few are PROD servers. As you see the host-names are sandwiched between two patterns:

1. First pattern is -x (lowercase x only),
2. Second pattern is either -UAT or -PRD. Whatever the string available in between first pattern and second pattern, we need to display.

note: From the first pattern x also should display in output. Example host name is: x01gmobdb2a

Answer

One using awk:

$ awk 'match($0,/-x[^-]*/){print substr($0,RSTART+1,RLENGTH-1)}' file
x01gmobdb2a
x01gtdsdb1a
x01gabcdb2a
x01gpqrdb1a
x01gxyzdb2a
x01guvwdb1a