First of all, you need this body preset.
https://www.mediafire.com/file/c186roylk2zhdpz/%255BVydartz-Vedora-Kingdom%255DHeightGiantResident.package/file
It a body preset that can make your sim become giant. It only work for vampire and only for adult to elder.
With this body preset. Your Sims might reach atleast about 2.4m in height, however, it still far from original Dimetrescu who are 2.9m.
You might need another 3 height sliders which can download below.
https://modthesims.info/d/559329/deprecated-see-description-for-info-height-slider-and-shorter-teens-mod-v1-97.html
https://simscommunity.info/2018/06/14/the-sims-4-height-slider-mod-now-available/
https://www.redheadsims-cc.com/2018/11/height-slider-collection.html
Use the body preset with these height slider can make your Sims reach 2.9m