Albeit 10+ years ago. I am trying to do similar to: @Chirag Jhaveri.

'column' # 1-4 displays OK. But # 5 won't display anything, no errors.

 <p:dataTable var="beWhereWhenMobile" value="#{beWhereWhenController.beWhereWhenByMobile}"
                     lazy="true"
                     style="width:100%"
                     rowKey="#{beWhereWhenMobile.id}"
                     border="1"
                     headerText="beWhereWhenMobile"
                     scrollable="false">

            <p:subTable var="events" value="#{beWhereWhenMobile.events}">

                <!-- 1 of 9 -->
                <!-- mobile -->
                <p:column visible="true">
                    <f:facet name="header">
                        <h:outputText value="beWhereWhenMobile mobile"/>
                    </f:facet>

                    <h:outputText value="#{beWhereWhenMobile.mobile}">
                    </h:outputText>
                </p:column>

                <!-- 2 of 9 -->
                <!-- events.eventName -->
                <p:column visible="true">
                    <f:facet name="header">
                        <h:outputText value="subTableBeWhereWhenMobile events eventName"/>
                    </f:facet>

                    <h:outputText value="#{events.eventName}">
                    </h:outputText>
                </p:column>

                <!-- 3 of 9 -->
                <!-- events.fromDateStart -->
                <p:column visible="true">
                    <f:facet name="header">
                        <h:outputText value="beWhereWhenMobile events fromDateStart"/>
                    </f:facet>

                    <h:outputText value="#{events.fromDateStart}">
                    </h:outputText>
                </p:column>

                <!-- 4 of 9 -->
                <!-- events.toDateEnd -->
                <p:column visible="true">
                    <f:facet name="header">
                        <h:outputText value="beWhereWhenMobile events toDateEnd"/>
                    </f:facet>

                    <h:outputText value="#{events.toDateEnd}">
                    </h:outputText>
                </p:column>
            </p:subTable>

            <p:subTable var="people" value="#{events.people}">
                <!-- 5 of 9 -->
                <!-- events.people.userName -->
                <p:column visible="true">
                    <f:facet name="header">
                        <h:outputText value="beWhereWhenMobile events people userName"/>
                    </f:facet>

                    <h:outputText value="#{people.userName}">
                    </h:outputText>
                </p:column>
            </p:subTable>
...
</>

Using:

• PrimeFaces: primefaces-14.0.7-jakart
• Jakarta Faces 4.1.1

TIA