var expressions = new[] {
Expression.Eq("DocAttrId", new decimal(-2)),
Expression.Eq("RowPos", new decimal(1)),
Expression.Eq("DocAttrId", new decimal(105510)),
Expression.Eq("DocAttrId", new decimal(-1)),
}
var ExGroup1 = Expression.Or(expressions[0], expressions[1]);
var ExGroup2 = Expression.And(expressions[2], ExGroup1);
var ExGroup3 = Expression.Or(expressions[3], ExGroup2);
_criteria.Add(ExGroup3);