Refer the following sample code for fetching the serial number from inventory details into advanced PDF template
<#list record.item as tranline>
<#assign serialNumbers =[]>
<#if tranline.inventorydetail?has_content>
<#if tranline.inventorydetail?contains(",")>
<#list tranline.inventorydetail?split("/>") as x><#assign serialNo = x?split(",")[0]><#assign serialNumbers = serialNumbers + [serialNo]/></#list>
<#else><#list tranline.inventorydetail?string?split("<br />") as x><#assign serialNumbers = serialNumbers + [x]/></#list>
</#if>
</#if>
<#list serialNumbers as val>
<tr>
<td colspan="2" > </td>
<td colspan="7" > </td>
<td colspan="10" > </td>
<td colspan="4" > </td>
<td colspan="7" >${val}</td>
</tr>
</#list>
</#list>