Fleet Tactical Personnel duty officer packs (available from fleet starbases) can grant Ground Warfare Specialists. Common quality packs (750 Fleet Credits) confirmed to drop. Unknown if available from regular Personnel packs or higher quality version, but suspect both availablities. As Starfleet character, I can confirm the following Common quality DOffs:
Rereh Evlem - Andorian Female - Founders of the Federation, Honorable, Stubborn - Increases damage vs Undine by 2.5%
Full extent of randomization unknown for species of officer, species specialized against, and DOff traits. If completely randomized, expect same availability of targeted species for both Space and Ground specialists, with different names for officers. If pulled from a list of pre-crated DOffs like cluster renown, expect similar variety instead.
Uncommon, Rare, and Very Rare DOffs suspected, but unable to confirm (can't buy in current fleet yet). Likely progression of damage values would be Common - 2.5%, Uncommon - 3.33% (or 3.3%, 3.35%, or 3.4%), Rare 4.15% (or 4.2%), Very Rare - 5%.