ListMetadataQuery[] query = new ListMetadataQuery[1];
query[0] = new ListMetadataQuery();
query[0].setType("CustomFeedFilter");
FileProperties[] x = lo.getMetadataConnection().listMetadata(query, 38.0);
for (FileProperties anX: x)
{
  System.out.println(anX);
}

<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
    <types>
       <members>Case.lessfeeds</members>
       <name>CustomFeedFilter</name>
    </types>
    <version>38.0</version>
</Package>

<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
    <types>
       <members>lessfeeds</members>
       <name>CustomFeedFilter</name>
    </types>
    <version>38.0</version>
</Package>

<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
    <types>
       <members>Opportunity.lessfeeds</members>
       <name>CustomFeedFilter</name>
    </types>
    <version>38.0</version>
</Package>