Power Query : Select a line from a list

[arth78]

Hello,

I'm a new user of PowerBI and I need your help to find a Power Query formula.

I have a column which contains a list of lines and I need to create a column which select a single line when it contains the expression "PRIO2". I'm probably not really understandable so I made a screen that explain what I want :

Can you help me to find the right Power Query formula to do that ?

Any help would be appreciated.