New to Qlik Sense

[karan_kn]

Create Flag for ID, If Value contains 'AA' then 'High' else 'Low'

[Bunim]

if(value='AA','High','Low')

[karan_kn]

not by value, the flag should be based on ID

Ex: 500001 is High, 500002 is low

[MarcoWedel]

Join (YourTable)
LOAD ID,
     If(Min(Value='AA'),'High','Low') as Flag
Resident YourTable
Group By ID;