In ${\mathrm{XeF}}_2$, molecule the angle between two lone pair orbitals is $\alpha$. the angle between lone pair orbital and bond pair orbital is $\beta$ and the angle between bond pair orbitals is $\gamma$ :

For  ${\mathrm{XeF}}_2$, molecule

The angle between two lone pair orbitals is $\alpha ={120}^{\circ }$

The angle between lone pair orbital and bond pair orbital is $\beta ={90}^{\circ }$ 

The angle between bond pair orbitals is $\gamma ={180}^{\circ }$ .

Hence the correct order is,$\gamma >\alpha >\beta$.