From my research, 2003 and before has a spin on filter under the hood and a non serviceable filter inside the transmission.
2004 and up, has just the internal filter. The internal filter requires transmission removal and disassembly to access.
There is no servicable transmission filter on the Sedona.
In transmission
The 2006 Kia Sedona does not have a replaceable transmission filter. So you only have to replace fluid, never the filter.
You don't, it doesn't have one
It is inside the transmission case. According to Kia, the filter is only replaced during overhaul of the transmission. You have to separate the case halves to replace the filter. This trans has no lower pan.
The transmission filter is located in the bottom of the transmission under the oil pan. You have to drop the oil pan to access it but the filter should come with a new gasket.
The 2004 Kia Sedona has a 5-speed automatic.
YES
The 2005 Kia Sedona has a 5-speed automatic.
The 2002 Kia Sedona has a 5-speed automatic.
The 2003 Kia Sedona has a 5-speed automatic.
The 2010 Kia Sedona has a 5-speed shiftable automatic.