Not sure what you're asking for...
If you're looking for a port expander - a Thunderbolt box that has USB, HDMI, eSATA, ethernet, audio, etc., then there are several options (Belkin, Caldigit, etc.).
If you're looking for a Thunderbolt port multiplier - like you do with a USB hub - then you're out of luck. The TB protocol does not permit port multipiers.