Checking the control of an entity
Assuming that entityMetadata.getAttributes() and attr.getAttributeType().getControls() returns some kind of Collection, the answer is an absolute YES.

entityMetadata.getAttributes().stream()
    .flatMap(attr -&gt; attr.getAttributeType().getControls().stream())
    .anyMatch(control -&gt; control.getIsMultiControl());


Other notes:


Comparing with == true is not necessary, that part could be removed entirely.
Prefixing interfaces with I is not something commonly done in Java, it is not recommended in any naming conventions. It is, however, done in C#. C# is not Java.
getIsMultiControl is a very weird name. Should preferably be named isMultiControl.