Reuse Flexformvalue in foreign_table_where
<p>After chosen a group, I want to visible all categories matching these groups. Is this possible?</p>

<pre><code>&lt;settings.flexform.categorygroups&gt;
                    &lt;TCEforms&gt;
                        &lt;label&gt;Category&lt;/label&gt;
                        &lt;displayCond&gt;FIELD:switchableControllerActions:=:Job-&gt;list&lt;/displayCond&gt;
                        &lt;config&gt;
                            &lt;type&gt;select&lt;/type&gt;
                            &lt;foreign_table&gt;tx_ext_domain_model_jobcategorygroup&lt;/foreign_table&gt;
                            &lt;minitems&gt;1&lt;/minitems&gt;
                            &lt;maxitems&gt;99&lt;/maxitems&gt;
                            &lt;size&gt;4&lt;/size&gt;
                        &lt;/config&gt;
                    &lt;/TCEforms&gt;
                &lt;/settings.flexform.categorygroups&gt;


&lt;settings.flexform.categories&gt;
                    &lt;TCEforms&gt;
                        &lt;label&gt;Category&lt;/label&gt;
                        &lt;displayCond&gt;FIELD:settings.flexform.categorygroups:REQ:true&lt;/displayCond&gt;
                        &lt;config&gt;
                            &lt;type&gt;select&lt;/type&gt;
                            &lt;foreign_table&gt;tx_ext_domain_model_jobcategory&lt;/foreign_table&gt;
                            &lt;foreign_table_where&gt;AND tx_ext_domain_model_jobcategory.job_category_group IN (###jobcategory###)&lt;/foreign_table_where&gt;
                            &lt;minitems&gt;1&lt;/minitems&gt;
                            &lt;maxitems&gt;99&lt;/maxitems&gt;
                            &lt;size&gt;4&lt;/size&gt;
                        &lt;/config&gt;
                    &lt;/TCEforms&gt;
                &lt;/settings.flexform.categories&gt;
</code></pre>

<p>How to fill this 'IN'?</p>