Thank you for pointing this out. It seems that all the following forms are equivalent:
In[692]:= {x->1}//Values//First
{x->1}//Last//Last
{x->1}//First//Last
Out[692]= 1
Out[693]= 1
Out[694]= 1
Therefore, I further collate the possible solutions to the problem here:
In[695]:= sol = {{x -> 1}, {x -> 5/4}, {x -> 5/8}};
ReverseSortBy[sol, Minus@*Abs@*Last@*First]
ReverseSortBy[sol, Minus@*Abs@*First@*Values]
SortBy[sol, Minus@*Abs@*Last@*First]
SortBy[sol, Minus@*Abs@*Last@*Last]
Out[696]= {{x -> 5/8}, {x -> 1}, {x -> 5/4}}
Out[697]= {{x -> 5/8}, {x -> 1}, {x -> 5/4}}
Out[698]= {{x -> 5/4}, {x -> 1}, {x -> 5/8}}
Out[699]= {{x -> 5/4}, {x -> 1}, {x -> 5/8}}
In[731]:=
s1={{x -> 1}, {x -> -5/4}, {x -> 5/8}};
ReverseSortBy[s1, (#//Values//First//Abs)&]
SortBy[s1, (#//Values//First//Abs)&]
Out[732]= {{x -> -(5/4)}, {x -> 1}, {x -> 5/8}}
Out[733]= {{x -> 5/8}, {x -> 1}, {x -> -(5/4)}}
Regards,
Zhao