[t1T2Instance: list_rs]

<td>${fieldValue(bean: t1T2Instance, field: "Accession_No")}</td>

Accession_No    [83]

<td>${fieldValue(bean: t1T2Instance, field: "Accession_No").join(' ')}</td>

String.metaClass.nob = { ->
   if(delegate.size() < 3) {
      return ""
   } else {
     return delegate[1..(delegate.size()-2)]
   }
}

${fieldValue(bean: someInstance, field: "tags").nob()}

<g:each in="${t1T2Instance}" var="instance" status="s">${(s==0) ? instance.Accession_No : ', '+instance.Accession_No}</g:each>

${t1T2Instance.collect{ it.Accession_No }.join(',')}