<o:validateMultiple components="input" validator="#{someBean.validate}"/>
<h:inputText id="input" value="#{someBean.value}" />

<o:validateMultiple components="inputCC" validator="#{someBean.validate}"/>
<myCC:myInputTextCompositeComponent id="inputCC" value="#{someBean.value}" />

at com.sun.faces.facelets.el.ContextualCompositeValueExpression.getValue(ContextualCompositeValueExpression.java:158) [jsf-impl-2.2.13.SP1.jar:2.2.13.SP1]
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109) [jsf-impl-2.2.13.SP1.jar:2.2.13.SP1]
at javax.faces.component.UIComponentBase$AttributesMap.get(UIComponentBase.java:2427) [jboss-jsf-api_2.2_spec-2.2.13.jar:2.2.13]
at com.sun.faces.el.CompositeComponentAttributesELResolver$ExpressionEvalMap.get(CompositeComponentAttributesELResolver.java:393) [jsf-impl-2.2.13.SP1.jar:2.2.13.SP1]
at javax.el.MapELResolver.getValue(MapELResolver.java:199) [jboss-el-api_3.0_spec-1.0.7.Final.jar:1.0.7.Final]
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176) [jsf-impl-2.2.13.SP1.jar:2.2.13.SP1]
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203) [jsf-impl-2.2.13.SP1.jar:2.2.13.SP1]
at com.sun.el.parser.AstValue.getValue(AstValue.java:139) [javax.el-impl-3.0.1-b08-jbossorg-1.jar:3.0.1-b08-jbossorg-1]
at com.sun.el.parser.AstValue.getValue(AstValue.java:203) [javax.el-impl-3.0.1-b08-jbossorg-1.jar:3.0.1-b08-jbossorg-1]
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:226) [javax.el-impl-3.0.1-b08-jbossorg-1.jar:3.0.1-b08-jbossorg-1]
at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50) [weld-core-impl-2.3.5.Final.jar:2.3.5.Final]
at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50) [weld-core-impl-2.3.5.Final.jar:2.3.5.Final]
at com.sun.faces.facelets.el.ContextualCompositeValueExpression.getValue(ContextualCompositeValueExpression.java:158) [jsf-impl-2.2.13.SP1.jar:2.2.13.SP1]