How can I search for a text inside a specific field
Matrix includes a query language called MRQL (Matrix Requirements Query Language) or Miracle in short..
One of its use is to search for a text in a specific field. For example to look for a Version field that contains the string 1.5 you can enter this into the search field, then press enter:
mrql:Version ~ "1.5"
More information about MRQL: MRQL