Creating custom variable

we have created the custom variable called “U Companyname” for the host/service template.
We have enabled the custom variable has been updated in the host template, but it’s not replicating in the service checks

Custom Variable:

Db2env : DB2DIR=/opt/IBM/db2/$host.vars.u_dbname Version
DB2INSTANCE=$host.vars.u_dbname$
INSTHOME=path/$host.vars.u_dbname$

Db2 Health Database $host.vars.u_dbname$
Db2 Health Mode stale-table-runstats
Db2 Health Username username
U Companyname $host.vars.u_CompanyName$
U Database DB2

Custom Variables
Customostype Linux
U Companyname DTAG
U Customer FDC
U Database DB2
U Dbname DBname

Request your assistance to understand what went wrong here.