Function Query Optimization

[Jae Joo]

I have the requirement to create field  - xyz to be returned based on the
matched result.
Here Is the code .

XYZ:concat(

    if(exists(query({!v='field1:12345'})), '<G>12345</G>', ''),

    if(exists(query({!v='field1:23456'})), '<G>23456</G>', ''),

    if(exists(query({!v='field1:34567'})), '<G>34567</G>', ''),

    if(exists(query({!v='field:45678'})), '<G>45678</G>','')
),

I am feeling this is very complex, so I am looking for some smart and
faster ideas.

Thanks,

Jae