It's not really clear what you are asking from this question alone but from the details of the other question it still seems as though flexbox is the solution as described by Oriol
.container {
background-color: gray;
display: flex;
overflow-x: hidden;
white-space: nowrap;
justify-content: space-between;
}
.first {
overflow: hidden;
text-overflow: ellipsis;
padding-right: 1em;
border: 1px solid red;
}
.third {
flex: 1;
text-align: right;
background:pink;
}
first div content
second div content
third div content
JSfiddle Demo