Filter does not process nested ${} variables

When I try filtering this under src/main/resources:
jms.username=${${env}.jms.username}

with this filtering strategy:
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>

Setting the property (from command line, <property>, etc.) fails to properly filter the nested element:
jms.username=${${env}.jms.username}

For example, I'd like the filter to convert to this (using a property of -Denv=dev):
jms.username=${dev.jms.username}